Personality and Individual Differences
Six items, two of them reverse-keyed, and four ways of scoring them — one right and three wrong in ways that leave almost no trace.
Simulated — a fictional scale and six fictional respondents
By the end you should be able to recode a reverse-keyed item correctly, and recognise in the item statistics when somebody has not.
About 20 minutes. Nothing you do here is saved or sent anywhere.
Six original items about persistence, answered 1 to 5. Two are worded so that agreement means less of the trait.
A researcher scores this scale and forgets to recode the two reverse-keyed items.
Nothing here changes the controls for you, and none of it says what you are going to find.
The same answers scored four different ways. Only one of them is right.
| Respondent | 1 | 2 | 3 (rev) | 4 | 5 (rev) | 6 | Total | Error |
|---|
| Item | Keying | Corrected item-total r | Reading |
|---|
Two reverse items, one respondent, one step at a time. Work out the recoded value and type it in.
Forgetting to recode lowers alpha and produces negative item-total correlations, and those are the symptoms usually taught. The consequence that matters is that individual scores are wrong and the respondents come out in the wrong order. Every correlation the scale then enters into is computed on those scores.
No recoding at all is loud: the reverse items correlate negatively with the rest of the scale, which anybody inspecting item statistics will see. Using the wrong scale maximum is silent. Every reverse answer comes out exactly one point too high, alpha hardly moves, no item looks anomalous, and the error survives peer review comfortably.
A researcher who understands perfectly well that "I give up on things once they become difficult" is reverse-worded, and leaves the number alone, has made exactly the same arithmetic error as somebody who never noticed. Comprehension and recoding are different operations, and only one of them is in the data.
Reverse items exist to counter acquiescence, and they work — the Response-Style Simulator in this module shows how. They also cost something. They are harder to understand, they are answered inconsistently by people reading quickly, they attract careless responding, and they routinely form their own factor in a factor analysis, which then gets mistaken for a second substantive dimension. Including them is a judgement, not an obligation.